Hey thanks for looking at the most brief Question I could type after days and days of frustration. I had upgraded from 17 to 18 and the 'Arnold' dlls would not initialize. After seven days of trying everything under the sun, AutoDesk tech support took a stab at it and stumped them too. It turned out Arnold requirements documents were not correct. The CPU requirement of SSE 4.1 was wrong, as SSE 4.2 was required and my CPU only supported SSE4.1. There were some other unexplained phenomena like user settings were not saving which may, or many not be related to SSE compatibility.FIX: Stick with 3DSMax 2017. While I have powerful machines they are just too old to work with Max 2018.

Thank you Stephan for your reply, however after extensive effort by AutoDesk tech support trying to get Max2018 to load, the only component that would not load was Arnold. They consulted your company and reported back to me that SSE 4.2 was required. Perhaps it only applied to Max2018? I don't know, I just know it stumped everyone and such was the answer provided to me by Autodesk. Beyond that I could not bear to burn anymore time struggling to make it work.